1. Field of the Invention
The present invention relates to a cathode ray tube in which a safety panel is bonded to a front surface of a panel with a resin layer and, more particularly to a method of and apparatus for peeling a safety panel so that the safety panel and a cathode tube envelope can be recycled.
2. Description of the Related Art
In conventional cathode ray tubes, there is a known design for a cathode ray tube 5 in which a safety panel 3 for anti-explosion protection is bonded to a front surface of a panel 2 of a cathode ray tube envelope 1 through a thermosetting resin layer (e.g., unsaturated polyester resin) 4. However, when it is determined that such cathode ray tube 5 is a defective product after the manufacturing process, then the safety panel 3 is peeled from the cathode ray tube envelope 1 so that the safety panel 3 and the cathode ray tube envelope 1 may each be recycled respectively.
One method of peeling the safety panel 3 that is bonded to the front surface of the panel 2 by the thermosetting resin layer 4, has heretofore been proposed in which a metal wire or piano wire is forced into a portion of the thermosetting resin layer 4 between the panel 2 and the safety panel 3 to cut the thermosetting resin layer 4 and to thereby peel the safety panel 3 from the panel 2.
This conventional method of peeling the safety panel 3 from the panel 2 has the following disadvantages:
(i) Since metal wire or piano wire is used, the safety panel 2 and the surface of the panel 2 of the cathode ray tube tend to be scratched and therefore cannot be recycled as easily. If they are scratched badly, then the cathode ray tube envelope will explode, which is very dangerous for workers. PA1 (ii) Inserting the metal wire or piano wire into the thermosetting resin layer 4 requires a worker with physical strength and skill, which unavoidably limits the workers. PA1 (iii) A portion of the resin remains in the inner surface of the safety panel 3 and the surface of the panel 2 of the cathode ray tube envelope 1 so that the safety panel 3 and the cathode ray tube envelop 1 are difficult to recycle. Furthermore, if the safety panel 3 and the cathode ray tube envelope 1 are discarded in the above-mentioned state, then this will lead to environmental problems.
Alternatively, there has heretofore been proposed a method in which only the cathode ray tube envelope 1 is recycled at the sacrifice of the safety panel 3. In this case, however, the safety panel 3 is very expensive and it is desired to recycle both the safety panel 3 and the cathode ray tube envelope 1.